190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Copyright (c) 2013 The Chromium Authors. All rights reserved. 290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// found in the LICENSE file. 490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#include "media/base/container_names.h" 690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#include <cctype> 890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#include <limits> 990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 1090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#include "base/basictypes.h" 1190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#include "base/logging.h" 1290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#include "media/base/bit_reader.h" 1390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 1490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)namespace media { 1590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 1690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)namespace container_names { 1790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 1890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#define TAG(a, b, c, d) \ 19116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch ((static_cast<uint32>(static_cast<uint8>(a)) << 24) | \ 20116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch (static_cast<uint32>(static_cast<uint8>(b)) << 16) | \ 21116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch (static_cast<uint32>(static_cast<uint8>(c)) << 8) | \ 22116680a4aac90f2aa7413d9095a592090648e557Ben Murdoch (static_cast<uint32>(static_cast<uint8>(d)))) 2390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 2490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#define RCHECK(x) \ 2590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) do { \ 2690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!(x)) \ 2790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return false; \ 2890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } while (0) 2990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 3090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)#define UTF8_BYTE_ORDER_MARK "\xef\xbb\xbf" 3190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 3290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Helper function to read 2 bytes (16 bits, big endian) from a buffer. 3390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int Read16(const uint8* p) { 3490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return p[0] << 8 | p[1]; 3590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 3690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 3790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Helper function to read 3 bytes (24 bits, big endian) from a buffer. 3890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static uint32 Read24(const uint8* p) { 3990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return p[0] << 16 | p[1] << 8 | p[2]; 4090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 4190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 4290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Helper function to read 4 bytes (32 bits, big endian) from a buffer. 4390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static uint32 Read32(const uint8* p) { 4490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3]; 4590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 4690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 4790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Helper function to read 4 bytes (32 bits, little endian) from a buffer. 4890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static uint32 Read32LE(const uint8* p) { 4990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return p[3] << 24 | p[2] << 16 | p[1] << 8 | p[0]; 5090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 5190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 5290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Helper function to do buffer comparisons with a string without going off the 5390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// end of the buffer. 5490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool StartsWith(const uint8* buffer, 5590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) size_t buffer_size, 5690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) const char* prefix) { 5790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) size_t prefix_size = strlen(prefix); 5890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (prefix_size <= buffer_size && 5990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) memcmp(buffer, prefix, prefix_size) == 0); 6090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 6190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 6290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Helper function to do buffer comparisons with another buffer (to allow for 6390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// embedded \0 in the comparison) without going off the end of the buffer. 6490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool StartsWith(const uint8* buffer, 6590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) size_t buffer_size, 6690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) const uint8* prefix, 6790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) size_t prefix_size) { 6890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (prefix_size <= buffer_size && 6990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) memcmp(buffer, prefix, prefix_size) == 0); 7090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 7190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 7290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Helper function to read up to 64 bits from a bit stream. 7390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static uint64 ReadBits(BitReader* reader, int num_bits) { 7490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) DCHECK_GE(reader->bits_available(), num_bits); 7590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) DCHECK((num_bits > 0) && (num_bits <= 64)); 7690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint64 value; 7790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader->ReadBits(num_bits, &value); 7890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return value; 7990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 8090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 8190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)const int kAc3FrameSizeTable[38][3] = { 8290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 128, 138, 192 }, { 128, 140, 192 }, { 160, 174, 240 }, { 160, 176, 240 }, 8390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 192, 208, 288 }, { 192, 210, 288 }, { 224, 242, 336 }, { 224, 244, 336 }, 8490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 256, 278, 384 }, { 256, 280, 384 }, { 320, 348, 480 }, { 320, 350, 480 }, 8590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 384, 416, 576 }, { 384, 418, 576 }, { 448, 486, 672 }, { 448, 488, 672 }, 8690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 512, 556, 768 }, { 512, 558, 768 }, { 640, 696, 960 }, { 640, 698, 960 }, 8790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 768, 834, 1152 }, { 768, 836, 1152 }, { 896, 974, 1344 }, 8890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 896, 976, 1344 }, { 1024, 1114, 1536 }, { 1024, 1116, 1536 }, 8990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 1280, 1392, 1920 }, { 1280, 1394, 1920 }, { 1536, 1670, 2304 }, 9090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 1536, 1672, 2304 }, { 1792, 1950, 2688 }, { 1792, 1952, 2688 }, 9190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 2048, 2228, 3072 }, { 2048, 2230, 3072 }, { 2304, 2506, 3456 }, 9290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 2304, 2508, 3456 }, { 2560, 2768, 3840 }, { 2560, 2770, 3840 } 9390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)}; 9490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 9590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for an ADTS AAC container. 9690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckAac(const uint8* buffer, int buffer_size) { 9790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Audio Data Transport Stream (ADTS) header is 7 or 9 bytes 9890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (from http://wiki.multimedia.cx/index.php?title=ADTS) 9990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 6); 10090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 10190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 10290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 6 < buffer_size) { 10390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 6); 10490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 10590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Syncword must be 0xfff. 10690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 12) == 0xfff); 10790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 10890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip MPEG version. 10990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1); 11090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 11190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Layer is always 0. 11290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 2) == 0); 11390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 11490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip protection + profile. 11590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 2); 11690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 11790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Check sampling frequency index. 11890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 4) != 15); // Forbidden. 11990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 12090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip private stream, channel configuration, originality, home, 12190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // copyrighted stream, and copyright_start. 12290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 3 + 1 + 1 + 1 + 1); 12390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 12490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Get frame length (includes header). 12590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int size = ReadBits(&reader, 13); 12690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(size > 0); 12790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += size; 12890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 12990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 13090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 13190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 13290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)const uint16 kAc3SyncWord = 0x0b77; 13390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 13490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for an AC3 container. 13590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckAc3(const uint8* buffer, int buffer_size) { 13690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ATSC Standard: Digital Audio Compression (AC-3, E-AC-3) 13790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Doc. A/52:2012 13890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (http://www.atsc.org/cms/standards/A52-2012(12-17).pdf) 13990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 14090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // AC3 container looks like syncinfo | bsi | audblk * 6 | aux | check. 14190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 6); 14290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 14390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 14490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 6 < buffer_size) { 14590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 6); 14690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 14790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Check syncinfo. 14890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 16) == kAc3SyncWord); 14990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 15090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip crc1. 15190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(16); 15290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 15390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify fscod. 15490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int sample_rate_code = ReadBits(&reader, 2); 15590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(sample_rate_code != 3); // Reserved. 15690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 15790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify frmsizecod. 15890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int frame_size_code = ReadBits(&reader, 6); 15990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(frame_size_code < 38); // Undefined. 16090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 16190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify bsid. 16290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 5) < 10); // Normally 8 or 6, 16 used by EAC3. 16390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 16490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += kAc3FrameSizeTable[frame_size_code][sample_rate_code]; 16590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 16690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 16790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 16890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 16990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for an EAC3 container (very similar to AC3) 17090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckEac3(const uint8* buffer, int buffer_size) { 17190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ATSC Standard: Digital Audio Compression (AC-3, E-AC-3) 17290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Doc. A/52:2012 17390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (http://www.atsc.org/cms/standards/A52-2012(12-17).pdf) 17490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 17590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // EAC3 container looks like syncinfo | bsi | audfrm | audblk* | aux | check. 17690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 6); 17790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 17890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 17990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 6 < buffer_size) { 18090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 6); 18190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 18290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Check syncinfo. 18390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 16) == kAc3SyncWord); 18490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 18590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify strmtyp. 18690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 2) != 3); 18790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 18890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip substreamid. 18990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(3); 19090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 19190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Get frmsize. Include syncinfo size and convert to bytes. 19290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int frame_size = (ReadBits(&reader, 11) + 1) * 2; 19390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(frame_size >= 7); 19490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 19590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip fscod, fscod2, acmod, and lfeon. 19690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(2 + 2 + 3 + 1); 19790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 19890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify bsid. 19990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int bit_stream_id = ReadBits(&reader, 5); 20090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(bit_stream_id >= 11 && bit_stream_id <= 16); 20190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 20290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += frame_size; 20390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 20490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 20590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 20690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 20790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Additional checks for a BINK container. 20890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckBink(const uint8* buffer, int buffer_size) { 20990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: http://wiki.multimedia.cx/index.php?title=Bink_Container 21090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size >= 44); 21190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 21290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify number of frames specified. 21390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(Read32LE(buffer + 8) > 0); 21490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 21590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify width in range. 21690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int width = Read32LE(buffer + 20); 21790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(width > 0 && width <= 32767); 21890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 21990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify height in range. 22090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int height = Read32LE(buffer + 24); 22190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(height > 0 && height <= 32767); 22290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 22390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify frames per second specified. 22490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(Read32LE(buffer + 28) > 0); 22590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 22690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify video frames per second specified. 22790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(Read32LE(buffer + 32) > 0); 22890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 22990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Number of audio tracks must be 256 or less. 23090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (Read32LE(buffer + 40) <= 256); 23190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 23290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 23390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Additional checks for a CAF container. 23490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckCaf(const uint8* buffer, int buffer_size) { 23590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: Apple Core Audio Format Specification 1.0 236868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) // (https://developer.apple.com/library/mac/#documentation/MusicAudio/Reference/CAFSpec/CAF_spec/CAF_spec.html) 23790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size >= 52); 23890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer, buffer_size); 23990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 24090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // mFileType should be "caff". 24190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 32) == TAG('c', 'a', 'f', 'f')); 24290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 24390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // mFileVersion should be 1. 24490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 16) == 1); 24590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 24690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip mFileFlags. 24790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(16); 24890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 24990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // First chunk should be Audio Description chunk, size 32l. 25090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 32) == TAG('d', 'e', 's', 'c')); 25190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 64) == 32); 25290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 25390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // CAFAudioFormat.mSampleRate(float64) not 0 25490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 64) != 0); 25590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 25690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // CAFAudioFormat.mFormatID not 0 25790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 32) != 0); 25890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 25990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip CAFAudioFormat.mBytesPerPacket and mFramesPerPacket. 26090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(32 + 32); 26190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 26290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // CAFAudioFormat.mChannelsPerFrame not 0 26390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 32) != 0); 26490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 26590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 26690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 26790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool kSamplingFrequencyValid[16] = { false, true, true, true, false, 26890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) false, true, true, true, false, 26990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) false, true, true, true, false, 27090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) false }; 27190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool kExtAudioIdValid[8] = { true, false, true, false, false, false, 27290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) true, false }; 27390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 27490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Additional checks for a DTS container. 27590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckDts(const uint8* buffer, int buffer_size) { 27690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ETSI TS 102 114 V1.3.1 (2011-08) 277868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) // (http://www.etsi.org/deliver/etsi_ts/102100_102199/102114/01.03.01_60/ts_102114v010301p.pdf) 27890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 11); 27990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 28090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 28190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 11 < buffer_size) { 28290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 11); 28390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 28490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify sync word. 28590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 32) == 0x7ffe8001); 28690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 28790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip frame type and deficit sample count. 28890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 5); 28990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 29090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify CRC present flag. 29190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 0); // CPF must be 0. 29290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 29390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify number of PCM sample blocks. 29490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 7) >= 5); 29590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 29690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify primary frame byte size. 29790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int frame_size = ReadBits(&reader, 14); 29890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(frame_size >= 95); 29990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 30090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip audio channel arrangement. 30190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(6); 30290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 30390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify core audio sampling frequency is an allowed value. 30490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(kSamplingFrequencyValid[ReadBits(&reader, 4)]); 30590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 30690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify transmission bit rate is valid. 30790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 5) <= 25); 30890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 30990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify reserved field is 0. 31090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 0); 31190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 31290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip dynamic range flag, time stamp flag, auxiliary data flag, and HDCD. 31390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 1 + 1 + 1); 31490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 31590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify extension audio descriptor flag is an allowed value. 31690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(kExtAudioIdValid[ReadBits(&reader, 3)]); 31790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 31890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip extended coding flag and audio sync word insertion flag. 31990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 1); 32090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 32190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify low frequency effects flag is an allowed value. 32290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 2) != 3); 32390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 32490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += frame_size + 1; 32590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 32690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 32790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 32890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 32990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for a DV container. 33090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckDV(const uint8* buffer, int buffer_size) { 33190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: SMPTE 314M (Annex A has differences with IEC 61834). 332868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) // (http://standards.smpte.org/content/978-1-61482-454-1/st-314-2005/SEC1.body.pdf) 33390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 11); 33490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 33590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 33690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int current_sequence_number = -1; 33790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int last_block_number[6]; 33890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 11 < buffer_size) { 33990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 11); 34090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 34190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Decode ID data. Sections 5, 6, and 7 are reserved. 34290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int section = ReadBits(&reader, 3); 34390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(section < 5); 34490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 34590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next bit must be 1. 34690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 1); 34790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 34890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip arbitrary bits. 34990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(4); 35090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 35190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int sequence_number = ReadBits(&reader, 4); 35290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 35390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip FSC. 35490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1); 35590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 35690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next 3 bits must be 1. 35790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 3) == 7); 35890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 35990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int block_number = ReadBits(&reader, 8); 36090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 36190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (section == 0) { // Header. 36290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Validate the reserved bits in the next 8 bytes. 36390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1); 36490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 0); 36590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 11) == 0x7ff); 36690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(4); 36790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 4) == 0xf); 36890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(4); 36990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 4) == 0xf); 37090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(4); 37190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 4) == 0xf); 37290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(3); 37390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 24) == 0xffffff); 37490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) current_sequence_number = sequence_number; 37590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) for (size_t i = 0; i < arraysize(last_block_number); ++i) 37690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) last_block_number[i] = -1; 37790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 37890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Sequence number must match (this will also fail if no header seen). 37990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(sequence_number == current_sequence_number); 38090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Block number should be increasing. 38190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(block_number > last_block_number[section]); 38290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) last_block_number[section] = block_number; 38390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 38490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 38590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Move to next block. 38690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 80; 38790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 38890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 38990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 39090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 39190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 39290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for a GSM container. 39390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckGsm(const uint8* buffer, int buffer_size) { 39490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ETSI EN 300 961 V8.1.1 395868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) // (http://www.etsi.org/deliver/etsi_en/300900_300999/300961/08.01.01_60/en_300961v080101p.pdf) 39690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // also http://tools.ietf.org/html/rfc3551#page-24 39790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // GSM files have a 33 byte block, only first 4 bits are fixed. 39890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size >= 1024); // Need enough data to do a decent check. 39990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 40090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 40190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset < buffer_size) { 40290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // First 4 bits of each block are xD. 40390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK((buffer[offset] & 0xf0) == 0xd0); 40490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 33; 40590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 40690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 40790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 40890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 40990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Advance to the first set of |num_bits| bits that match |start_code|. |offset| 41090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// is the current location in the buffer, and is updated. |bytes_needed| is the 41190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// number of bytes that must remain in the buffer when |start_code| is found. 41290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Returns true if start_code found (and enough space in the buffer after it), 41390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// false otherwise. 41490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool AdvanceToStartCode(const uint8* buffer, 41590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int buffer_size, 41690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int* offset, 41790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int bytes_needed, 41890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int num_bits, 41990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint32 start_code) { 42090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) DCHECK_GE(bytes_needed, 3); 42190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) DCHECK_LE(num_bits, 24); // Only supports up to 24 bits. 42290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 42390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Create a mask to isolate |num_bits| bits, once shifted over. 42490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint32 bits_to_shift = 24 - num_bits; 42590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint32 mask = (1 << num_bits) - 1; 42690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (*offset + bytes_needed < buffer_size) { 42790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint32 next = Read24(buffer + *offset); 42890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (((next >> bits_to_shift) & mask) == start_code) 42990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 43090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++(*offset); 43190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 43290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return false; 43390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 43490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 43590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for an H.261 container. 43690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckH261(const uint8* buffer, int buffer_size) { 43790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ITU-T Recommendation H.261 (03/1993) 43890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (http://www.itu.int/rec/T-REC-H.261-199303-I/en) 43990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 16); 44090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 44190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 44290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) bool seen_start_code = false; 44390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (true) { 44490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Advance to picture_start_code, if there is one. 44590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!AdvanceToStartCode(buffer, buffer_size, &offset, 4, 20, 0x10)) { 44690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // No start code found (or off end of buffer), so success if 44790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // there was at least one valid header. 44890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return seen_start_code; 44990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 45090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 45190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Now verify the block. AdvanceToStartCode() made sure that there are 45290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // at least 4 bytes remaining in the buffer. 45390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, buffer_size - offset); 45490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 20) == 0x10); 45590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 45690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip the temporal reference and PTYPE. 45790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(5 + 6); 45890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 45990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip any extra insertion information. Since this is open-ended, if we run 46090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // out of bits assume that the buffer is correctly formatted. 46190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int extra = ReadBits(&reader, 1); 46290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (extra == 1) { 46390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!reader.SkipBits(8)) 46490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return seen_start_code; 46590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!reader.ReadBits(1, &extra)) 46690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return seen_start_code; 46790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 46890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 46990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next should be a Group of Blocks start code. Again, if we run out of 47090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // bits, then assume that the buffer up to here is correct, and the buffer 47190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // just happened to end in the middle of a header. 47290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int next; 47390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!reader.ReadBits(16, &next)) 47490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return seen_start_code; 47590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(next == 1); 47690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 47790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Move to the next block. 47890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) seen_start_code = true; 47990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 4; 48090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 48190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 48290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 48390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for an H.263 container. 48490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckH263(const uint8* buffer, int buffer_size) { 48590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ITU-T Recommendation H.263 (01/2005) 48690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (http://www.itu.int/rec/T-REC-H.263-200501-I/en) 48790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // header is PSC(22b) + TR(8b) + PTYPE(8+b). 48890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 16); 48990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 49090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 49190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) bool seen_start_code = false; 49290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (true) { 49390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Advance to picture_start_code, if there is one. 49490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!AdvanceToStartCode(buffer, buffer_size, &offset, 9, 22, 0x20)) { 49590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // No start code found (or off end of buffer), so success if 49690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // there was at least one valid header. 49790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return seen_start_code; 49890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 49990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 50090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Now verify the block. AdvanceToStartCode() made sure that there are 50190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // at least 9 bytes remaining in the buffer. 50290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 9); 50390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 22) == 0x20); 50490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 50590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip the temporal reference. 50690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(8); 50790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 50890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify that the first 2 bits of PTYPE are 10b. 50990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 2) == 2); 51090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 51190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip the split screen indicator, document camera indicator, and full 51290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // picture freeze release. 51390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 1 + 1); 51490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 51590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify Source Format. 51690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int format = ReadBits(&reader, 3); 51790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(format != 0 && format != 6); // Forbidden or reserved. 51890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 51990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (format == 7) { 52090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify full extended PTYPE. 52190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int ufep = ReadBits(&reader, 3); 52290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (ufep == 1) { 52390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify the optional part of PLUSPTYPE. 52490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) format = ReadBits(&reader, 3); 52590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(format != 0 && format != 7); // Reserved. 52690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(11); 52790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next 4 bits should be b1000. 52890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 4) == 8); // Not allowed. 52990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 53090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ufep == 0); // Only 0 and 1 allowed. 53190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 53290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 53390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify picture type code is not a reserved value. 53490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int picture_type_code = ReadBits(&reader, 3); 53590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(picture_type_code != 6 && picture_type_code != 7); // Reserved. 53690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 53790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip picture resampling mode, reduced resolution mode, 53890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // and rounding type. 53990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 1 + 1); 54090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 54190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next 3 bits should be b001. 54290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 3) == 1); // Not allowed. 54390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 54490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 54590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Move to the next block. 54690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) seen_start_code = true; 54790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 9; 54890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 54990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 55090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 55190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for an H.264 container. 55290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckH264(const uint8* buffer, int buffer_size) { 55390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ITU-T Recommendation H.264 (01/2012) 55490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (http://www.itu.int/rec/T-REC-H.264) 55590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Section B.1: Byte stream NAL unit syntax and semantics. 55690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 4); 55790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 55890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 55990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int parameter_count = 0; 56090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (true) { 56190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Advance to picture_start_code, if there is one. 56290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!AdvanceToStartCode(buffer, buffer_size, &offset, 4, 24, 1)) { 56390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // No start code found (or off end of buffer), so success if 56490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // there was at least one valid header. 56590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return parameter_count > 0; 56690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 56790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 56890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Now verify the block. AdvanceToStartCode() made sure that there are 56990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // at least 4 bytes remaining in the buffer. 57090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 4); 57190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 24) == 1); 57290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 57390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify forbidden_zero_bit. 57490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 0); 57590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 57690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Extract nal_ref_idc and nal_unit_type. 57790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int nal_ref_idc = ReadBits(&reader, 2); 57890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int nal_unit_type = ReadBits(&reader, 5); 57990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 58090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (nal_unit_type) { 58190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 5: // Coded slice of an IDR picture. 58290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(nal_ref_idc != 0); 58390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 58490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 6: // Supplemental enhancement information (SEI). 58590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 9: // Access unit delimiter. 58690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 10: // End of sequence. 58790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 11: // End of stream. 58890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 12: // Filler data. 58990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(nal_ref_idc == 0); 59090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 59190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 7: // Sequence parameter set. 59290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 8: // Picture parameter set. 59390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++parameter_count; 59490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 59590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 59690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 59790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip the current start_code_prefix and move to the next. 59890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 4; 59990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 60090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 60190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 60290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const char kHlsSignature[] = "#EXTM3U"; 60390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const char kHls1[] = "#EXT-X-STREAM-INF:"; 60490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const char kHls2[] = "#EXT-X-TARGETDURATION:"; 60590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const char kHls3[] = "#EXT-X-MEDIA-SEQUENCE:"; 60690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 60790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Additional checks for a HLS container. 60890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckHls(const uint8* buffer, int buffer_size) { 60990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // HLS is simply a play list used for Apple HTTP Live Streaming. 61090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: Apple HTTP Live Streaming Overview 61190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (http://goo.gl/MIwxj) 61290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 61390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (StartsWith(buffer, buffer_size, kHlsSignature)) { 61490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Need to find "#EXT-X-STREAM-INF:", "#EXT-X-TARGETDURATION:", or 61590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // "#EXT-X-MEDIA-SEQUENCE:" somewhere in the buffer. Other playlists (like 61690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // WinAmp) only have additional lines with #EXTINF 61790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (http://en.wikipedia.org/wiki/M3U). 61890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = strlen(kHlsSignature); 61990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset < buffer_size) { 62090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer[offset] == '#') { 62190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (StartsWith(buffer + offset, buffer_size - offset, kHls1) || 62290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) StartsWith(buffer + offset, buffer_size - offset, kHls2) || 62390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) StartsWith(buffer + offset, buffer_size - offset, kHls3)) { 62490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 62590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 62690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 62790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++offset; 62890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 62990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 63090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return false; 63190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 63290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 63390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for a MJPEG stream. 63490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckMJpeg(const uint8* buffer, int buffer_size) { 63590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ISO/IEC 10918-1 : 1993(E), Annex B 63690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (http://www.w3.org/Graphics/JPEG/itu-t81.pdf) 63790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size >= 16); 63890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 63990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 64090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int last_restart = -1; 64190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int num_codes = 0; 64290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 5 < buffer_size) { 64390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Marker codes are always a two byte code with the first byte xFF. 64490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer[offset] == 0xff); 64590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint8 code = buffer[offset + 1]; 64690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(code >= 0xc0 || code == 1); 64790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 64890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip sequences of xFF. 64990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (code == 0xff) { 65090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++offset; 65190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) continue; 65290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 65390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 65490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Success if the next marker code is EOI (end of image) 65590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (code == 0xd9) 65690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 65790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 65890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Check remaining codes. 65990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (code == 0xd8 || code == 1) { 66090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // SOI (start of image) / TEM (private use). No other data with header. 66190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 2; 66290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else if (code >= 0xd0 && code <= 0xd7) { 66390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // RST (restart) codes must be in sequence. No other data with header. 66490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int restart = code & 0x07; 66590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (last_restart >= 0) 66690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(restart == (last_restart + 1) % 8); 66790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) last_restart = restart; 66890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 2; 66990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 67090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // All remaining marker codes are followed by a length of the header. 67190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int length = Read16(buffer + offset + 2) + 2; 67290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 67390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Special handling of SOS (start of scan) marker since the entropy 67490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // coded data follows the SOS. Any xFF byte in the data block must be 67590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // followed by x00 in the data. 67690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (code == 0xda) { 67790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int number_components = buffer[offset + 4]; 67890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(length == 8 + 2 * number_components); 67990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 68090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Advance to the next marker. 68190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += length; 68290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 2 < buffer_size) { 68390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer[offset] == 0xff && buffer[offset + 1] != 0) 68490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 68590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++offset; 68690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 68790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 68890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip over the marker data for the other marker codes. 68990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += length; 69090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 69190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 69290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++num_codes; 69390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 69490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (num_codes > 1); 69590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 69690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 69790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)enum Mpeg2StartCodes { 69890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) PROGRAM_END_CODE = 0xb9, 69990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) PACK_START_CODE = 0xba 70090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)}; 70190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 70290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for a MPEG2 Program Stream. 70390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckMpeg2ProgramStream(const uint8* buffer, int buffer_size) { 70490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ISO/IEC 13818-1 : 2000 (E) / ITU-T Rec. H.222.0 (2000 E). 70590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 14); 70690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 70790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 70890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 14 < buffer_size) { 70990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 14); 71090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 71190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Must start with pack_start_code. 71290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 24) == 1); 71390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 8) == PACK_START_CODE); 71490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 71590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Determine MPEG version (MPEG1 has b0010, while MPEG2 has b01). 71690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int mpeg_version = ReadBits(&reader, 2); 71790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (mpeg_version == 0) { 71890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // MPEG1, 10 byte header 71990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Validate rest of version code 72090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 2) == 2); 72190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 72290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(mpeg_version == 1); 72390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 72490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 72590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip system_clock_reference_base [32..30]. 72690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(3); 72790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 72890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify marker bit. 72990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 1); 73090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 73190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip system_clock_reference_base [29..15]. 73290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(15); 73390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 73490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify next marker bit. 73590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 1); 73690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 73790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip system_clock_reference_base [14..0]. 73890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(15); 73990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 74090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify next marker bit. 74190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 1); 74290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 74390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (mpeg_version == 0) { 74490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify second marker bit. 74590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 1); 74690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 74790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip mux_rate. 74890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(22); 74990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 75090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify next marker bit. 75190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 1); 75290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 75390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Update offset to be after this header. 75490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 12; 75590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 75690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Must be MPEG2. 75790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip program_mux_rate. 75890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(22); 75990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 76090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify pair of marker bits. 76190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 2) == 3); 76290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 76390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip reserved. 76490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(5); 76590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 76690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Update offset to be after this header. 76790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int pack_stuffing_length = ReadBits(&reader, 3); 76890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 14 + pack_stuffing_length; 76990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 77090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 77190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Check for system headers and PES_packets. 77290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 6 < buffer_size && Read24(buffer + offset) == 1) { 77390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next 8 bits determine stream type. 77490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int stream_id = buffer[offset + 3]; 77590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 77690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Some stream types are reserved and shouldn't occur. 77790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (mpeg_version == 0) 77890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(stream_id != 0xbc && stream_id < 0xf0); 77990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else 78090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(stream_id != 0xfc && stream_id != 0xfd && stream_id != 0xfe); 78190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 78290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Some stream types are used for pack headers. 78390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (stream_id == PACK_START_CODE) // back to outer loop. 78490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 78590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (stream_id == PROGRAM_END_CODE) // end of stream. 78690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 78790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 78890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int pes_length = Read16(buffer + offset + 4); 78990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(pes_length > 0); 79090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset = offset + 6 + pes_length; 79190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 79290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 79390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Success as we are off the end of the buffer and liked everything 79490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // in the buffer. 79590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 79690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 79790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 79890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)const uint8 kMpeg2SyncWord = 0x47; 79990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 80090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for a MPEG2 Transport Stream. 80190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckMpeg2TransportStream(const uint8* buffer, int buffer_size) { 80290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Spec: ISO/IEC 13818-1 : 2000 (E) / ITU-T Rec. H.222.0 (2000 E). 80390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Normal packet size is 188 bytes. However, some systems add various error 80490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // correction data at the end, resulting in packet of length 192/204/208 80590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // (https://en.wikipedia.org/wiki/MPEG_transport_stream). Determine the 80690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // length with the first packet. 80790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size >= 250); // Want more than 1 packet to check. 80890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 80990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 81090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int packet_length = -1; 81190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (buffer[offset] != kMpeg2SyncWord && offset < 20) { 81290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip over any header in the first 20 bytes. 81390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++offset; 81490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 81590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 81690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 6 < buffer_size) { 81790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 6); 81890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 81990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Must start with sync byte. 82090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 8) == kMpeg2SyncWord); 82190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 82290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip transport_error_indicator, payload_unit_start_indicator, and 82390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // transport_priority. 82490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 1 + 1); 82590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 82690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify the pid is not a reserved value. 82790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int pid = ReadBits(&reader, 13); 82890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(pid < 3 || pid > 15); 82990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 83090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip transport_scrambling_control. 83190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(2); 83290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 83390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Adaptation_field_control can not be 0. 83490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int adaptation_field_control = ReadBits(&reader, 2); 83590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(adaptation_field_control != 0); 83690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 83790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // If there is an adaptation_field, verify it. 83890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (adaptation_field_control >= 2) { 83990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip continuity_counter. 84090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(4); 84190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 84290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Get adaptation_field_length and verify it. 84390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int adaptation_field_length = ReadBits(&reader, 8); 84490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (adaptation_field_control == 2) 84590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(adaptation_field_length == 183); 84690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else 84790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(adaptation_field_length <= 182); 84890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 84990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 85090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Attempt to determine the packet length on the first packet. 85190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (packet_length < 0) { 85290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer[offset + 188] == kMpeg2SyncWord) 85390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) packet_length = 188; 85490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else if (buffer[offset + 192] == kMpeg2SyncWord) 85590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) packet_length = 192; 85690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else if (buffer[offset + 204] == kMpeg2SyncWord) 85790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) packet_length = 204; 85890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else 85990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) packet_length = 208; 86090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 86190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += packet_length; 86290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 86390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 86490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 86590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 86690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)enum Mpeg4StartCodes { 86790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VISUAL_OBJECT_SEQUENCE_START_CODE = 0xb0, 86890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VISUAL_OBJECT_SEQUENCE_END_CODE = 0xb1, 86990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VISUAL_OBJECT_START_CODE = 0xb5, 87090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VOP_START_CODE = 0xb6 87190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)}; 87290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 87390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for a raw MPEG4 bitstream container. 87490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckMpeg4BitStream(const uint8* buffer, int buffer_size) { 87590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Defined in ISO/IEC 14496-2:2001. 87690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // However, no length ... simply scan for start code values. 87790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Note tags are very similar to H.264. 87890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 4); 87990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 88090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 88190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int sequence_start_count = 0; 88290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int sequence_end_count = 0; 88390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int visual_object_count = 0; 88490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int vop_count = 0; 88590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (true) { 88690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Advance to start_code, if there is one. 88790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!AdvanceToStartCode(buffer, buffer_size, &offset, 6, 24, 1)) { 88890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Not a complete sequence in memory, so return true if we've seen a 88990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // visual_object_sequence_start_code and a visual_object_start_code. 89090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (sequence_start_count > 0 && visual_object_count > 0); 89190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 89290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 89390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Now verify the block. AdvanceToStartCode() made sure that there are 89490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // at least 6 bytes remaining in the buffer. 89590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 6); 89690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 24) == 1); 89790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 89890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int start_code = ReadBits(&reader, 8); 89990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(start_code < 0x30 || start_code > 0xaf); // 30..AF and 90090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(start_code < 0xb7 || start_code > 0xb9); // B7..B9 reserved 90190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 90290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (start_code) { 90390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case VISUAL_OBJECT_SEQUENCE_START_CODE: { 90490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++sequence_start_count; 90590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify profile in not one of many reserved values. 90690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int profile = ReadBits(&reader, 8); 90790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile > 0); 90890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x04 || profile > 0x10); 90990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x13 || profile > 0x20); 91090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x23 || profile > 0x31); 91190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x35 || profile > 0x41); 91290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x43 || profile > 0x60); 91390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x65 || profile > 0x70); 91490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x73 || profile > 0x80); 91590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x83 || profile > 0x90); 91690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0x95 || profile > 0xa0); 91790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0xa4 || profile > 0xb0); 91890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0xb5 || profile > 0xc0); 91990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0xc3 || profile > 0xd0); 92090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile < 0xe4); 92190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 92290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 92390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 92490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case VISUAL_OBJECT_SEQUENCE_END_CODE: 92590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(++sequence_end_count == sequence_start_count); 92690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 92790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 92890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case VISUAL_OBJECT_START_CODE: { 92990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++visual_object_count; 93090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (ReadBits(&reader, 1) == 1) { 93190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int visual_object_verid = ReadBits(&reader, 4); 93290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(visual_object_verid > 0 && visual_object_verid < 3); 93390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 3) != 0); 93490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 93590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int visual_object_type = ReadBits(&reader, 4); 93690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(visual_object_type > 0 && visual_object_type < 6); 93790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 93890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 93990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 94090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case VOP_START_CODE: 94190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(++vop_count <= visual_object_count); 94290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 94390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 94490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip this block. 94590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 6; 94690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 94790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 94890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 94990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Additional checks for a MOV/QuickTime/MPEG4 container. 95090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckMov(const uint8* buffer, int buffer_size) { 95190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: ISO/IEC 14496-12:2005(E). 952868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) // (http://standards.iso.org/ittf/PubliclyAvailableStandards/c061988_ISO_IEC_14496-12_2012.zip) 95390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 8); 95490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 95590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 95690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 8 < buffer_size) { 9575b892326406927b709cdaf6c384d4ababf456332Ben Murdoch uint32 atomsize = Read32(buffer + offset); 95890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint32 atomtype = Read32(buffer + offset + 4); 95990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Only need to check for ones that are valid at the top level. 96090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (atomtype) { 96190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('f','t','y','p'): 96290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('p','d','i','n'): 96390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('m','o','o','v'): 96490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('m','o','o','f'): 96590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('m','f','r','a'): 96690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('m','d','a','t'): 96790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('f','r','e','e'): 96890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('s','k','i','p'): 96990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('m','e','t','a'): 97090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('m','e','c','o'): 97190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('s','t','y','p'): 97290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('s','i','d','x'): 97390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('s','s','i','x'): 97490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('p','r','f','t'): 97590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('b','l','o','c'): 97690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 97790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) default: 97890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return false; 97990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 98090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (atomsize == 1) { 98190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Indicates that the length is the next 64bits. 98290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (offset + 16 > buffer_size) 98390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 98490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (Read32(buffer + offset + 8) != 0) 98590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; // Offset is way past buffer size. 98690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) atomsize = Read32(buffer + offset + 12); 98790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 9885b892326406927b709cdaf6c384d4ababf456332Ben Murdoch if (atomsize == 0 || atomsize > static_cast<size_t>(buffer_size)) 989a36e5920737c6adbddd3e43b760e5de8431db6e0Torne (Richard Coles) break; // Indicates the last atom or length too big. 99090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += atomsize; 99190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 99290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 99390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 99490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 99590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)enum MPEGVersion { 99690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VERSION_25 = 0, 99790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VERSION_RESERVED, 99890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VERSION_2, 99990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VERSION_1 100090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)}; 100190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)enum MPEGLayer { 100290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) L_RESERVED = 0, 100390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) LAYER_3, 100490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) LAYER_2, 100590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) LAYER_1 100690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)}; 100790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 100890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int kSampleRateTable[4][4] = { { 11025, 12000, 8000, 0 }, // v2.5 100990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 0, 0, 0, 0 }, // not used 101090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 22050, 24000, 16000, 0 }, // v2 101190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) { 44100, 48000, 32000, 0 } // v1 101290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)}; 101390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 101490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int kBitRateTableV1L1[16] = { 0, 32, 64, 96, 128, 160, 192, 224, 256, 101590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 288, 320, 352, 384, 416, 448, 0 }; 101690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int kBitRateTableV1L2[16] = { 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 101790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 192, 224, 256, 320, 384, 0 }; 101890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int kBitRateTableV1L3[16] = { 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 101990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 160, 192, 224, 256, 320, 0 }; 102090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int kBitRateTableV2L1[16] = { 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 102190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 160, 176, 192, 224, 256, 0 }; 102290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int kBitRateTableV2L23[16] = { 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 102390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 112, 128, 144, 160, 0 }; 102490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 102590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool ValidMpegAudioFrameHeader(const uint8* header, 102690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int header_size, 102790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int* framesize) { 102890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: http://mpgedit.org/mpgedit/mpeg_format/mpeghdr.htm. 102990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) DCHECK_GE(header_size, 4); 103090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) *framesize = 0; 103190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(header, 4); // Header can only be 4 bytes long. 103290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 103390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify frame sync (11 bits) are all set. 103490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 11) == 0x7ff); 103590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 103690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify MPEG audio version id. 103790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int version = ReadBits(&reader, 2); 103890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(version != 1); // Reserved. 103990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 104090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify layer. 104190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int layer = ReadBits(&reader, 2); 104290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(layer != 0); 104390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 104490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip protection bit. 104590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1); 104690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 104790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify bitrate index. 104890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int bitrate_index = ReadBits(&reader, 4); 104990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(bitrate_index != 0xf); 105090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 105190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify sampling rate frequency index. 105290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int sampling_index = ReadBits(&reader, 2); 105390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(sampling_index != 3); 105490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 105590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Get padding bit. 105690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int padding = ReadBits(&reader, 1); 105790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 105890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Frame size: 105990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // For Layer I files = (12 * BitRate / SampleRate + Padding) * 4 106090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // For others = 144 * BitRate / SampleRate + Padding 106190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Unfortunately, BitRate and SampleRate are coded. 106290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int sampling_rate = kSampleRateTable[version][sampling_index]; 106390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int bitrate; 106490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (version == VERSION_1) { 106590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (layer == LAYER_1) 106690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) bitrate = kBitRateTableV1L1[bitrate_index]; 106790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else if (layer == LAYER_2) 106890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) bitrate = kBitRateTableV1L2[bitrate_index]; 106990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else 107090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) bitrate = kBitRateTableV1L3[bitrate_index]; 107190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 107290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (layer == LAYER_1) 107390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) bitrate = kBitRateTableV2L1[bitrate_index]; 107490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else 107590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) bitrate = kBitRateTableV2L23[bitrate_index]; 107690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 107790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (layer == LAYER_1) 107890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) *framesize = ((12000 * bitrate) / sampling_rate + padding) * 4; 107990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) else 108090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) *framesize = (144000 * bitrate) / sampling_rate + padding; 108190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (bitrate > 0 && sampling_rate > 0); 108290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 108390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 108490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Extract a size encoded the MP3 way. 108590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int GetMp3HeaderSize(const uint8* buffer, int buffer_size) { 108690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) DCHECK_GE(buffer_size, 9); 108790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int size = ((buffer[6] & 0x7f) << 21) + ((buffer[7] & 0x7f) << 14) + 108890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ((buffer[8] & 0x7f) << 7) + (buffer[9] & 0x7f) + 10; 108990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer[5] & 0x10) // Footer added? 109090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) size += 10; 109190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return size; 109290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 109390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 109490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Additional checks for a MP3 container. 109590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckMp3(const uint8* buffer, int buffer_size, bool seenHeader) { 109690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size >= 10); // Must be enough to read the initial header. 109790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 109890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int framesize; 109990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int numSeen = 0; 110090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 110190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (seenHeader) { 110290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset = GetMp3HeaderSize(buffer, buffer_size); 110390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 110490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip over leading 0's. 110590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset < buffer_size && buffer[offset] == 0) 110690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++offset; 110790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 110890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 110990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (offset + 3 < buffer_size) { 111090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ValidMpegAudioFrameHeader( 111190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) buffer + offset, buffer_size - offset, &framesize)); 111290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 111390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Have we seen enough valid headers? 111490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (++numSeen > 10) 111590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 111690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += framesize; 111790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 111890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Off the end of the buffer, return success if a few valid headers seen. 111990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return numSeen > 2; 112090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 112190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 112290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Check that the next characters in |buffer| represent a number. The format 112390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// accepted is optional whitespace followed by 1 or more digits. |max_digits| 112490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// specifies the maximum number of digits to process. Returns true if a valid 112590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// number is found, false otherwise. 112690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool VerifyNumber(const uint8* buffer, 112790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int buffer_size, 112890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int* offset, 112990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int max_digits) { 113090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(*offset < buffer_size); 113190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 113290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip over any leading space. 113390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (isspace(buffer[*offset])) { 113490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++(*offset); 113590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(*offset < buffer_size); 113690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 113790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 113890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Need to process up to max_digits digits. 113990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int numSeen = 0; 114090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (--max_digits >= 0 && isdigit(buffer[*offset])) { 114190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++numSeen; 114290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++(*offset); 114390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (*offset >= buffer_size) 114490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; // Out of space but seen a digit. 114590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 114690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 114790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Success if at least one digit seen. 114890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (numSeen > 0); 114990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 115090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 115190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Check that the next character in |buffer| is one of |c1| or |c2|. |c2| is 115290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// optional. Returns true if there is a match, false if no match or out of 115390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// space. 115490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static inline bool VerifyCharacters(const uint8* buffer, 115590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int buffer_size, 115690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int* offset, 115790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) char c1, 115890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) char c2) { 115990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(*offset < buffer_size); 116090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) char c = static_cast<char>(buffer[(*offset)++]); 116190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (c == c1 || (c == c2 && c2 != 0)); 116290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 116390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 116490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for a SRT container. 116590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckSrt(const uint8* buffer, int buffer_size) { 116690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: http://en.wikipedia.org/wiki/SubRip 116790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 20); 116890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 116990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // First line should just be the subtitle sequence number. 117090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = StartsWith(buffer, buffer_size, UTF8_BYTE_ORDER_MARK) ? 3 : 0; 117190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 100)); 117290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, '\n', '\r')); 117390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 117490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip any additional \n\r. 117590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (VerifyCharacters(buffer, buffer_size, &offset, '\n', '\r')) {} 117690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) --offset; // Since VerifyCharacters() gobbled up the next non-CR/LF. 117790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 117890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Second line should look like the following: 117990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // 00:00:10,500 --> 00:00:13,000 118090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Units separator can be , or . 118190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 100)); 118290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, ':', 0)); 118390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 2)); 118490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, ':', 0)); 118590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 2)); 118690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, ',', '.')); 118790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 3)); 118890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, ' ', 0)); 118990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, '-', 0)); 119090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, '-', 0)); 119190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, '>', 0)); 119290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, ' ', 0)); 119390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 100)); 119490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, ':', 0)); 119590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 2)); 119690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, ':', 0)); 119790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 2)); 119890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyCharacters(buffer, buffer_size, &offset, ',', '.')); 119990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(VerifyNumber(buffer, buffer_size, &offset, 3)); 120090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 120190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 120290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 120390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Read a Matroska Element Id. 120490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static int GetElementId(BitReader* reader) { 120590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Element ID is coded with the leading zero bits (max 3) determining size. 120690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // If it is an invalid encoding or the end of the buffer is reached, 120790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // return -1 as a tag that won't be expected. 120890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (reader->bits_available() >= 8) { 120990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int num_bits_to_read = 0; 121090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) static int prefix[] = { 0x80, 0x4000, 0x200000, 0x10000000 }; 121190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) for (int i = 0; i < 4; ++i) { 121290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) num_bits_to_read += 7; 121390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (ReadBits(reader, 1) == 1) { 121490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (reader->bits_available() < num_bits_to_read) 121590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 121690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // prefix[] adds back the bits read individually. 121790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return ReadBits(reader, num_bits_to_read) | prefix[i]; 121890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 121990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 122090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 122190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Invalid encoding, return something not expected. 122290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return -1; 122390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 122490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 122590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Read a Matroska Unsigned Integer (VINT). 122690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static uint64 GetVint(BitReader* reader) { 122790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Values are coded with the leading zero bits (max 7) determining size. 122890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // If it is an invalid coding or the end of the buffer is reached, 122990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // return something that will go off the end of the buffer. 123090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (reader->bits_available() >= 8) { 123190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int num_bits_to_read = 0; 123290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) for (int i = 0; i < 8; ++i) { 123390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) num_bits_to_read += 7; 123490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (ReadBits(reader, 1) == 1) { 123590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (reader->bits_available() < num_bits_to_read) 123690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 123790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return ReadBits(reader, num_bits_to_read); 123890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 123990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 124090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 124190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Incorrect format (more than 7 leading 0's) or off the end of the buffer. 124290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Since the return value is used as a byte size, return a value that will 124390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // cause a failure when used. 124490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (reader->bits_available() / 8) + 2; 124590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 124690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 124790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Additional checks for a WEBM container. 124890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckWebm(const uint8* buffer, int buffer_size) { 124990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: http://www.matroska.org/technical/specs/index.html 125090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size > 12); 125190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 125290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer, buffer_size); 125390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 125490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify starting Element Id. 125590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(GetElementId(&reader) == 0x1a45dfa3); 125690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 125790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Get the header size, and ensure there are enough bits to check. 125890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int header_size = GetVint(&reader); 125990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(reader.bits_available() / 8 >= header_size); 126090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 126190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Loop through the header. 126290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (reader.bits_available() > 0) { 126390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int tag = GetElementId(&reader); 126490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int tagsize = GetVint(&reader); 126590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (tag) { 126690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x4286: // EBMLVersion 126790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x42f7: // EBMLReadVersion 126890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x42f2: // EBMLMaxIdLength 126990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x42f3: // EBMLMaxSizeLength 127090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x4287: // DocTypeVersion 127190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x4285: // DocTypeReadVersion 127290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xec: // void 127390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xbf: // CRC32 127490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(reader.SkipBits(tagsize * 8)); 127590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 127690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 127790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x4282: // EBMLDocType 127890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Need to see "webm" or "matroska" next. 127990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (ReadBits(&reader, 32)) { 128090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('w', 'e', 'b', 'm') : 128190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 128290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('m', 'a', 't', 'r') : 128390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (ReadBits(&reader, 32) == TAG('o', 's', 'k', 'a')); 128490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 128590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return false; 128690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 128790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) default: // Unrecognized tag 128890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return false; 128990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 129090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 129190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return false; 129290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 129390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 129490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)enum VC1StartCodes { 129590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VC1_FRAME_START_CODE = 0x0d, 129690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VC1_ENTRY_POINT_START_CODE = 0x0e, 129790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) VC1_SEQUENCE_START_CODE = 0x0f 129890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)}; 129990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 130090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Checks for a VC1 bitstream container. 130190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static bool CheckVC1(const uint8* buffer, int buffer_size) { 130290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Reference: SMPTE 421M 1303868fa2fe829687343ffae624259930155e16dbd8Torne (Richard Coles) // (http://standards.smpte.org/content/978-1-61482-555-5/st-421-2006/SEC1.body.pdf) 130490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // However, no length ... simply scan for start code values. 130590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Expect to see SEQ | [ [ ENTRY ] PIC* ]* 130690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Note tags are very similar to H.264. 130790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 130890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(buffer_size >= 24); 130990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 131090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // First check for Bitstream Metadata Serialization (Annex L) 131190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer[0] == 0xc5 && 131290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) Read32(buffer + 4) == 0x04 && 131390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) Read32(buffer + 20) == 0x0c) { 131490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Verify settings in STRUCT_C and STRUCT_A 131590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + 8, 12); 131690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 131790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int profile = ReadBits(&reader, 4); 131890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (profile == 0 || profile == 4) { // simple or main 131990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip FRMRTQ_POSTPROC, BITRTQ_POSTPROC, and LOOPFILTER. 132090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(3 + 5 + 1); 132190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 132290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next bit must be 0. 132390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 0); 132490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 132590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip MULTIRES. 132690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1); 132790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 132890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next bit must be 1. 132990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 1); 133090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 133190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip FASTUVMC, EXTENDED_MV, DQUANT, and VSTRANSFORM. 133290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 1 + 2 + 1); 133390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 133490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next bit must be 0. 133590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 0); 133690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 133790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Skip OVERLAP, SYNCMARKER, RANGERED, MAXBFRAMES, QUANTIZER, and 133890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // FINTERPFLAG. 133990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) reader.SkipBits(1 + 1 + 1 + 3 + 2 + 1); 134090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 134190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next bit must be 1. 134290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 1) == 1); 134390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 134490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } else { 134590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(profile == 12); // Other profile values not allowed. 134690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 28) == 0); 134790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 134890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 134990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Now check HORIZ_SIZE and VERT_SIZE, which must be 8192 or less. 135090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 32) <= 8192); 135190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 32) <= 8192); 135290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return true; 135390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 135490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 135590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Buffer isn't Bitstream Metadata, so scan for start codes. 135690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 0; 135790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int sequence_start_code = 0; 135890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int frame_start_code = 0; 135990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) while (true) { 136090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Advance to start_code, if there is one. 136190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (!AdvanceToStartCode(buffer, buffer_size, &offset, 5, 24, 1)) { 136290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Not a complete sequence in memory, so return true if we've seen a 136390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // sequence start and a frame start (not checking entry points since 136490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // they only occur in advanced profiles). 136590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return (sequence_start_code > 0 && frame_start_code > 0); 136690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 136790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 136890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Now verify the block. AdvanceToStartCode() made sure that there are 136990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // at least 5 bytes remaining in the buffer. 137090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) BitReader reader(buffer + offset, 5); 137190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 24) == 1); 137290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 137390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Keep track of the number of certain types received. 137490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (ReadBits(&reader, 8)) { 137590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case VC1_SEQUENCE_START_CODE: { 137690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++sequence_start_code; 137790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (ReadBits(&reader, 2)) { 137890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0: // simple 137990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 1: // main 138090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 2) == 0); 138190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 138290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 2: // complex 138390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return false; 138490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 3: // advanced 138590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 3) <= 4); // Verify level = 0..4 138690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(ReadBits(&reader, 2) == 1); // Verify colordiff_format = 1 138790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 138890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 138990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 139090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 139190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 139290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case VC1_ENTRY_POINT_START_CODE: 139390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // No fields in entry data to check. However, it must occur after 139490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // sequence header. 139590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) RCHECK(sequence_start_code > 0); 139690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 139790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 139890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case VC1_FRAME_START_CODE: 139990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) ++frame_start_code; 140090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 140190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 140290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) offset += 5; 140390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 140490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 140590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 140690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// For some formats the signature is a bunch of characters. They are defined 140790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// below. Note that the first 4 characters of the string may be used as a TAG 140890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// in LookupContainerByFirst4. For signatures that contain embedded \0, use 140990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// uint8[]. 141090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const char kAmrSignature[] = "#!AMR"; 141190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const uint8 kAsfSignature[] = { 0x30, 0x26, 0xb2, 0x75, 0x8e, 0x66, 0xcf, 141290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 0x11, 0xa6, 0xd9, 0x00, 0xaa, 0x00, 0x62, 141390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 0xce, 0x6c }; 141490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const char kAssSignature[] = "[Script Info]"; 141590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const char kAssBomSignature[] = UTF8_BYTE_ORDER_MARK "[Script Info]"; 141690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static const uint8 kWtvSignature[] = { 0xb7, 0xd8, 0x00, 0x20, 0x37, 0x49, 0xda, 141790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 0x11, 0xa6, 0x4e, 0x00, 0x07, 0xe9, 0x5e, 141890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 0xad, 0x8d }; 141990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 142090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Attempt to determine the container type from the buffer provided. This is 142190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// a simple pass, that uses the first 4 bytes of the buffer as an index to get 142290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// a rough idea of the container format. 142390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)static MediaContainerName LookupContainerByFirst4(const uint8* buffer, 142490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int buffer_size) { 142590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Minimum size that the code expects to exist without checking size. 142690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer_size < 12) 142790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_UNKNOWN; 142890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 142990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint32 first4 = Read32(buffer); 143090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (first4) { 143190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x1a45dfa3: 143290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckWebm(buffer, buffer_size)) 143390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_WEBM; 143490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 143590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 143690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x3026b275: 143790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (StartsWith(buffer, 143890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) buffer_size, 143990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) kAsfSignature, 144090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) sizeof(kAsfSignature))) { 144190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_ASF; 144290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 144390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 144490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 144590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('#','!','A','M'): 144690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (StartsWith(buffer, buffer_size, kAmrSignature)) 144790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_AMR; 144890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 144990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 145090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('#','E','X','T'): 145190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckHls(buffer, buffer_size)) 145290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_HLS; 145390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 145490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 145590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('.','R','M','F'): 145690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer[4] == 0 && buffer[5] == 0) 145790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_RM; 145890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 145990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 146090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('.','r','a','\xfd'): 146190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_RM; 146290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 146390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('B','I','K','b'): 146490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('B','I','K','d'): 146590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('B','I','K','f'): 146690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('B','I','K','g'): 146790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('B','I','K','h'): 146890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('B','I','K','i'): 146990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckBink(buffer, buffer_size)) 147090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_BINK; 147190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 147290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 147390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('c','a','f','f'): 147490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckCaf(buffer, buffer_size)) 147590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_CAF; 147690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 147790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 147890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('D','E','X','A'): 147990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer_size > 15 && 148090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) Read16(buffer + 11) <= 2048 && 148190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) Read16(buffer + 13) <= 2048) { 148290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_DXA; 148390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 148490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 148590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 148690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('D','T','S','H'): 148790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (Read32(buffer + 4) == TAG('D','H','D','R')) 148890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_DTSHD; 148990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 149090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 149190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x64a30100: 149290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x64a30200: 149390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x64a30300: 149490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x64a30400: 149590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x0001a364: 149690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x0002a364: 149790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x0003a364: 149890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (Read32(buffer + 4) != 0 && Read32(buffer + 8) != 0) 149990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_IRCAM; 150090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 150190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 150290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('f','L','a','C'): 150390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_FLAC; 150490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 150590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('F','L','V',0): 150690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('F','L','V',1): 150790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('F','L','V',2): 150890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('F','L','V',3): 150990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('F','L','V',4): 151090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer[5] == 0 && Read32(buffer + 5) > 8) 151190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_FLV; 151290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 151390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 151490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('F','O','R','M'): 151590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (Read32(buffer + 8)) { 151690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('A','I','F','F'): 151790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('A','I','F','C'): 151890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_AIFF; 151990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 152090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 152190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 152290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('M','A','C',' '): 152390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_APE; 152490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 152590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('O','N','2',' '): 152690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (Read32(buffer + 8) == TAG('O','N','2','f')) 152790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_AVI; 152890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 152990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 153090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('O','g','g','S'): 153190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer[5] <= 7) 153290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_OGG; 153390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 153490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 153590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('R','F','6','4'): 153690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (buffer_size > 16 && Read32(buffer + 12) == TAG('d','s','6','4')) 153790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_WAV; 153890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 153990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 154090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('R','I','F','F'): 154190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (Read32(buffer + 8)) { 154290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('A','V','I',' '): 154390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('A','V','I','X'): 154490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('A','V','I','\x19'): 154590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('A','M','V',' '): 154690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_AVI; 154790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('W','A','V','E'): 154890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_WAV; 154990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 155090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 155190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 155290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('[','S','c','r'): 155390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (StartsWith(buffer, buffer_size, kAssSignature)) 155490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_ASS; 155590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 155690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 155790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('\xef','\xbb','\xbf','['): 155890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (StartsWith(buffer, buffer_size, kAssBomSignature)) 155990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_ASS; 156090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 156190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 156290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x7ffe8001: 156390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xfe7f0180: 156490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0x1fffe800: 156590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xff1f00e8: 156690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckDts(buffer, buffer_size)) 156790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_DTS; 156890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 156990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 157090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xb7d80020: 157190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (StartsWith(buffer, 157290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) buffer_size, 157390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) kWtvSignature, 157490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) sizeof(kWtvSignature))) { 157590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_WTV; 157690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 157790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 157890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 157990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 158090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Now try a few different ones that look at something other 158190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // than the first 4 bytes. 158290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint32 first3 = first4 & 0xffffff00; 158390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (first3) { 158490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('C','W','S',0): 158590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('F','W','S',0): 158690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_SWF; 158790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 158890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case TAG('I','D','3',0): 158990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckMp3(buffer, buffer_size, true)) 159090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_MP3; 159190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 159290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 159390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 159490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Maybe the first 2 characters are something we can use. 159590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) uint32 first2 = Read16(buffer); 159690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) switch (first2) { 159790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case kAc3SyncWord: 159890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckAc3(buffer, buffer_size)) 159990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_AC3; 160090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckEac3(buffer, buffer_size)) 160190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_EAC3; 160290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 160390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 160490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xfff0: 160590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xfff1: 160690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xfff8: 160790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) case 0xfff9: 160890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckAac(buffer, buffer_size)) 160990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_AAC; 161090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) break; 161190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 161290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 161390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Check if the file is in MP3 format without the header. 161490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckMp3(buffer, buffer_size, false)) 161590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_MP3; 161690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 161790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_UNKNOWN; 161890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 161990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 162090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)// Attempt to determine the container name from the buffer provided. 162190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)MediaContainerName DetermineContainer(const uint8* buffer, int buffer_size) { 162290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) DCHECK(buffer); 162390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 162490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Since MOV/QuickTime/MPEG4 streams are common, check for them first. 162590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckMov(buffer, buffer_size)) 162690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_MOV; 162790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 162890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Next attempt the simple checks, that typically look at just the 162990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // first few bytes of the file. 163090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) MediaContainerName result = LookupContainerByFirst4(buffer, buffer_size); 163190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (result != CONTAINER_UNKNOWN) 163290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return result; 163390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 163490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // Additional checks that may scan a portion of the buffer. 163590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckMpeg2ProgramStream(buffer, buffer_size)) 163690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_MPEG2PS; 163790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckMpeg2TransportStream(buffer, buffer_size)) 163890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_MPEG2TS; 163990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckMJpeg(buffer, buffer_size)) 164090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_MJPEG; 164190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckDV(buffer, buffer_size)) 164290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_DV; 164390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckH261(buffer, buffer_size)) 164490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_H261; 164590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckH263(buffer, buffer_size)) 164690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_H263; 164790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckH264(buffer, buffer_size)) 164890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_H264; 164990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckMpeg4BitStream(buffer, buffer_size)) 165090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_MPEG4BS; 165190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckVC1(buffer, buffer_size)) 165290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_VC1; 165390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckSrt(buffer, buffer_size)) 165490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_SRT; 165590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckGsm(buffer, buffer_size)) 165690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_GSM; 165790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 165890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // AC3/EAC3 might not start at the beginning of the stream, 165990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) // so scan for a start code. 166090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) int offset = 1; // No need to start at byte 0 due to First4 check. 166190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (AdvanceToStartCode(buffer, buffer_size, &offset, 4, 16, kAc3SyncWord)) { 166290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckAc3(buffer + offset, buffer_size - offset)) 166390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_AC3; 166490dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) if (CheckEac3(buffer + offset, buffer_size - offset)) 166590dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_EAC3; 166690dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) } 166790dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 166890dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) return CONTAINER_UNKNOWN; 166990dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} 167090dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 167190dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} // namespace container_names 167290dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles) 167390dce4d38c5ff5333bea97d859d4e484e27edf0cTorne (Richard Coles)} // namespace media 1674